Homeless Bulgarian Deyan Deyanov, 29, was convicted of murder by a jury of nine at the Provincial Court in Santa Cruz de Tenerife on Friday.

He repeatedly stabbed and beheaded Jennifer Mills-Westley, 60, while she was shopping in the popular resort of Los Cristianos in the Canary Islands, Spain, on May 13 2011.

In a written sentence, magistrate Maria Jesus Garcia Sanchez imposed the toughest tariff available for the schizophrenic, who the jury found had diminished responsibility for his crime.

She also ordered that Deyanov, who was living rough when he randomly murdered Ms Mills-Westley, should pay her daughters, Sarah and Samantha Mills-Westley, 100,000 euros.

During a four-day trial, Deyanov denied murder and said he did not recognise himself in CCTV footage of the attack shown to the jury. He also claimed to hear voices which tell him he is an "angel of Jesus Christ", sent to create a new Jerusalem.

In her written sentence Ms Garcia Sanchez said she took into account the "criminal danger" Deyanov represented. She said Ms Mills-Westley, a retired road safety worker originally from Norwich, had had no chance given the "forceful and unexpected" nature of the attack she suffered.

She added: "Frequently, homicidal intent is something which must be inferred. In this case, homicidal intent exists without a doubt and inferences are unnecessary."

After the trial, Sarah Mills-Westley, 43, from Norwich, and Samantha, 39, who lives in the Midi-Pyrenees region of France, said a "catalogue of failings" by "a number of authorities" led to their mother's death.

They said: "We would like to make a plea that the care of people like Deyan Valentinov Deyanov is taken more seriously. He is a young man who has clearly been failed by a number of authorities, in the UK, Spain and most likely others."